Michael Schumacher revealed to be the Stig's alter ego.

[Xithras]

Yes, people have speculated about a possible connection for years, but Top Gear yesterday revealed that the Stig hides his true identity by donning a Michael Schumacher outfit whenever he's not filming TG episodes. There are even rumors that the Stig has been unfairly racing against mere mortal drivers while wearing this "Schumacher" costume, a practice that I hope racing authorities will put an end to.

Video of the reveal:
http://news.bbc.co.uk/2/hi/uk_news/8111984.stm

Links:
http://www.edmunds.com/insideline/do/News/articleId=151008
http://www.dailymail.co.uk/tvshowbiz/article-1194383/Unmasked-But-Top-Gears-Stig-REALLY-F1-ace-Michael-Schumacher.html

Conspiracy theories that it's all a big joke and that Schumacher isn't the Stig after all:
http://www.crash.net/f1/news/148773/1/is_the_stig_really_michael_schumacher.html
http://en.f1-live.com/f1/en/headlines/news/detail/090622092912.shtml
“I don’t think Michael Schumacher is The Stig. I think we made it up” - Jeremy Clarkson.

[flvegan]

1. Odd that the time they finally get the FXX on their track, Stig turns out

to be Ferrari's Schumacher.

I think there are a few Stig drivers. Matter of fact...some say, The Stig is a vegan who lives in Florida surrounded by dogs and wears his racing suit in the bathtub.

Shumacher is a diversion from the "rumors" from a few months ago that Stiggie had been unmasked as another driver.

[Ikonoklast]

2. Can't be.

The Stig eats live small mammals, and that isn't a racing suit, it's his actual skin.

It has been heard that The Stig can go without breathing for up to three days at a time, and never has to blink.